Flatbed scanners are designed in such a way that a large sheet of glass (typically 8 1/2".times.11" or larger), which defines a scanning surface of the scanner, is used to position an image such as a document or object to be scanned, mechanically and optically with respect to a scanning mechanism of the scanner. Since the scanning surface is in the optical path of the image to be scanned, artifacts such as dirt, dust and/or scratches degrade the quality of the image to be scanned. As a result, these artifacts must be controlled and/or removed. Dirt and dust can be easily controlled by way of dust covers, and, any dirt or dust that does end up on the scanning surface can easily be cleaned. On the other hand, scratches caused by, for example, scissors, staplers, knives or other scratch producing objects are permanent and cannot be removed. It is therefore imperative that one try to minimize the generation of scratches on the scanning surface of a scanner.
Some known processes of making glass scratch or abrasion-resistant involve the application of diamond or diamond-like particles to the glass, or the application of an organic coating to the glass, (see, for example, U.S. Pat. Nos. 5,492,769 and 4,471,016). These processes tend to be complicated and costly. Therefore, the concept of scratch resistance coatings on the scanning surface of a scanner can add cost to a price sensitive commodity. Further, these processes do not provide for a surface which can prevent or minimize scratches from diamonds such as on diamond rings. Scratch resistance coatings may also compromise the optical path and, therefore, the quality of the scanned image. Since scanner manufacturers can control scratches during manufacturing, this becomes a quality and cost repair/replacement issue for the end user or product manufacturer. Since scanner usage can typically be quite high, this is usually a re-occurring significant cost. In one application of thermal printers today, this cost can result in approximately 5% of product cost.
FIG. 1 illustrates a typical conventional flatbed scanner 7. Flatbed scanner 7 includes a dust cover 9 and a scanning surface 11 in the form of a glass pane or plate. In normal operation, a user lifts dust cover 9 to expose scanning surface 11. During this time frame, when dust cover 9 is left open, large foreign objects such as scissors, staplers, knives or other scratch producing objects can be placed upon scanning surface 11 and moved around so as to cause scratches on scanning surface 11. Next, an image to be scanned 14 such as a document or object is placed upon scanning surface 11 and aligned. During placement of image to be scanned 14, it is very typical for rings (sometimes with diamonds), metal watches, watch bands, metal cuff links, etc. to rub against scanning surface 11 to cause scratches to occur. It also noted that one can easily access scanning surface 11 directly with ones wrist area where watches, bracelets and chains can exist, and the underside finger area (where diamond rings protrude) when placing image to be scanned 14. Also, nothing prevents bottom side access (when the image to be scanned is between fingers) with the back side of the fingers rubbing across scanning surface 11.